The ancient Beikou is situated at the Yanshan sierra located at Miyun County northeast, the coiled dragon, lies the tiger two Shannan surface nearby mountains rolling country.

• 古北口位于密云县东北部地处燕山山脉，蟠龙、卧虎两山南面的浅山丘陵区。潮河从北部山谷峡口流入密云水库。